1. Technical Field
The invention relates to Quality of Service (QoS) mechanisms, particularly for wireless transmission but also relates to the detection and treatment of degraded QoS across any kind of network boundary.
2. Discussion of Related Art
The current solutions for packet traffic in the wireless radio link do not support mechanisms for guaranteed QoS.
There are new QoS mechanisms under development for application in fixed network routers. However, the function of radio network elements, i.e., the radio network controller and the user equipment is significantly different from those of a router. Typically, a router handles multiple input streams and provides multiple outputs streams extremely fast. The packets are delivered to the next network node depending on the destination address with the help of routing tables.
When packets arrive in a radio network controller, they are not routed based on the IP address anymore, but using the radio network specific user equipment (UE) addresses. The packets can be delivered through different transmission channels called dedicated channels, common channels or shared channels. The essential difference as compared to a fixed network is that the traffic shares common radio resources. The radio resource is scarce and changes dynamically due to changes in the traffic load, but also due to the radio characteristics. The radio network subsystem (RNS) is characterized in that it can control the radio resource dynamically and share it in a fair manner or close to optimal manner. The RNS is also characterized in that it is planned and dimensioned to provide coverage and capacity over a certain service area and targeted to satisfy the subscribers' needs. The capacity and coverage depend on the location, mobility and traffic type of the UE, but also it depends on the location, mobility and traffic type of the other UEs in the same RNS.
The problem is simply that there is no support for satisfying different QoS requirements over the air interface. Actually there is traditionally not even QoS mechanisms for the fixed network. However, as suggested above, recent effort has resulted in a number of QoS mechanisms for the internet protocol (IP) traffic in the fixed network. The field is still more or less open to guarantee the QoS over the air interface. Only the most simple and traditional means are known as giving different requirements for the bearers like the minimum guaranteed bit-rate requirement, maximum allowed service data unit (SDU) size and assigning each bearer a priority.